This invention relates to a concrete forming system and, more particularly, to a novel form tie for maintaining the sidewalls of a concrete form in desired spaced-apart relationships.
Concrete forms made of a polymeric foam material are known. Such forms basically comprise a pair of laterally spaced-apart sidewalls presenting a cavity therebetween. A plurality of these forms are connected to present longitudinally and vertically aligned cavities for pouring concrete therein.
One problem with the use of concrete forms is that the sidewall pairs must be immobilized so as to resist pressures on the walls during transport and, more importantly, during concrete pouring and curing. If not, the form sidewalls may shift in lateral and/or vertical and/or longitudinal directions. Such displacements make it difficult to easily connect the forms. Also, the forms may separate along the joints respectively presented along the zones of connection between longitudinally and vertically adjacent forms. If not sufficiently braced the concrete can cause these joints to separate. The industry refers to such separations as xe2x80x9cblow outsxe2x80x9d.
Accordingly, various form tie devices, e.g., braces and permanent tension members, have been proposed so as to maintain the sidewalls in place to preclude such shifting and/or xe2x80x9cblow outsxe2x80x9d. However, such devices have been relatively complex in construction requiring the sidewalls to have special configurations so as to utilize the form ties.
In response thereto we have invented novel form ties for use in concrete forms which effectively interface with the form sidewalls so as to maintain the walls in a desired spatial relationship during transport as well as concrete pouring and curing. Our forms also automatically present a longitudinally extended seat for easily positioning horizontal rebar in the cavity formed between the sidewalls.
It is therefore a general object of this invention to provide a novel form tie for use in a concrete forming system.
A further object of this invention is to provide a form tie, as aforesaid, which is incorporated in the concrete form during the blow molding thereof.
Another general object of this invention is to provide a form tie, as aforesaid, which resists loads that impart tension, compression, bending, twisting and lateral stresses acting thereon.
Still a further object of this invention is to provide a form tie, as aforesaid, which diminishes the lateral, vertical and longitudinal displacement of adjacent sidewalls of a concrete form during transport and use.
Another particular object of this invention is to provide a form tie, as aforesaid, which enhances on-site assembly of the concrete forms, inclusive of the placement of horizontal rebar therein.
A further object of this invention is to provide a form tie, as aforesaid, which effectively resists the forces arising from concrete flow but without interference with the concrete flow in the cavity between the form sidewalls and between adjacent forms.
A particular object of this invention is to provide a form tie, as aforesaid, having a web which extends at an angle across the cavity so as to resist the forces acting thereon.
Another object of this invention is to provide a form tie, as aforesaid, wherein the web includes a sloped surface used to present a seat for placement of a longitudinally extending rebar therein.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, a now preferred embodiment of this invention.